Coming Soon: Your Local Earthquake Forecasts?

John Roachfor National Geographic News

September 17, 2004

In life, few events happen in isolation. Earthquakes are no exception. Scientists are now developing computer models that show how an earthquake in one area can increase or decrease the potential for earthquakes in adjacent areas.

University of California, Davis, computational physicist John Rundle is a member of the QuakeSim project team, a NASA-sponsored initiative to develop the computer models.

Rundle says that within a decade, these models may be able to forecast some types of earthquakes with accuracy similar to that of current forecasts for hurricane paths.

However, he noted that scientists have indications that there may be different classes of earthquakes and that quite possibly some earthquakes are inherently unpredictable, he said.

One scientist leading Rundle and his colleagues on the quest for new earthquake computer models is Andrea Donnellan. A geophysicist, Donnellan is QuakeSim's principal investigator at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.

"We're currently aiming for five- to ten-year forecasts at a resolution of about 10 kilometers [6.2 miles]," she said.

A 10-kilometer resolution corresponds to a magnitude 6 earthquake. Such earthquakes are strong enough to damage poorly constructed buildings and other structures that lie within 10 kilometers from the epicenter of an earthquake.

Donnellan says the first generation suite of QuakeSim software packages, which will focus on southern California, should be complete within six months.

Earthquake Processes

The Earth's surface is divided into about a dozen thin shells of crust, commonly known as continental plates. These plates move as a result of motions in the Earth's interior.

Where these shells push against each other, stress builds up. The force grows until it overcomes the strength of rocks and dirt found in the different layers at the boundary. The result is an earthquake.